Projectile propelling system



Jan. 26, 1960 J. w. TREAT, JR 2,922,341

PROJECTILE PROPELLING SYSTEM Filed Nov. 7, 1955 4 Sheets-Sheet 1 FIGUREl FIGURE 2 FIGURE 3 INVENTOR. FIGURE 4 JOHN W.TREATJR ATT RNEY Jan. 26,1960 J. w. TREAT, JR 2,922,341

PROJECTILE PROPELLING SYSTEM Filed Nov. 7, 1955 4 Sheets-Sheet 2 h mmnwEw mmDwE ir...| w. WWO

INVENTOR. JOHN W TREATJR 3;]

ATT RNEY Jan. 26, 1960 J. w. TREAT, JR

PROJECTILE PROPELLING SYSTEM 0- mmDoI 4 Sheets-Sheet 3 INVENTOR. JOHN W.TREATJR ATTORNEY Filed NOV. 7, 1955 Jan. 26, 1960 J. w. TREAT, JR

PROJECTILE PROPELLING SYSTEM Filed Nov. 7, 1955 4 Sheets-Sheet 4 mmDQEINVENTOR- JOHN W.TREATJR BY Z ATT RNEY mwww United States Patent2,922,341 ,PROJECTILE PRorE LiNG SYSTEM John W. Treat, In, East Hampton,C'onn., assignor to glin Mathieson Chemical Corporation, New Haven,

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Application November 7, 1955, Serial No. 545,290

3 Claims. (Cl. 89-7) This invention relates to an improved method andmeans for propelling a projectile with a liquid propellant and moreparticularly to a gun system capable of using liquid mono-propellantregeneratively injected into an initially dry chamber by pneumatic meansinitiated by aprimer.

Heretofore, firearms employing liquid propellants generally wereopen-ended chambers, the open end being sealed by a caseless projectile.A liquid propellant having a high vapor pressure would be pumped intothe chamber and then the mixture was ignited, generally with a sparkplug to drive the projectile down the bore and out the muzzle of thegun. (See US. 1,343,456 and US. 1,359,295.) Due to difficulties insealing the liquid propelalnt within the chamber and in ignition, theseguns have never become popular. Solid propellant type guns employingcased ammunition, the case containing a percussion type primer were morepopular because they were simpler and more convenient to use andrequired less complicated gun actions.

Several features possible with liquid propellants have, nevertheless,obviated complete abandonment 'of the production of liquid propellanttype guns. The ease in storing and loading, the lack of a need for grainformation, the possibility of an easier means for efiecting progressiveburning or regenerative injection similar to that disclosed in US.1,297,798 or U.S. 2,360,217 for solid propellants and other attractivefeatures of a liquid propellant gun have always been the deterrentagainst its complete abandonment. gun system never proved feasible.

An object of this invention is to provide a novel method and means forpropelling a projectile with a liquid propellant. Another object of thisinvention is to provide a propellant system for a firearm capable ofusing a mono-propellant as its main charge. Another object of thisinvention is to provide a propellant system embodying regenerativeinjection of the propellant so as to accomplisli energy utilization of ahigh degree. A further object of this invention is to provide apropellant system having an adjustable regenerative injection rate. Afurther object of this invention is to provide a firearm using a liquidpropellant with pyrotechnic ignition. Another object of thisinvention'is to provide a firearm which commences operation from a drychamber. Another object of this invention is to provide a firearm which,through its use of a dry chamber enables seals simpler than heretoforeemployed in liquid propellant type guns. Another object of thisinvention is to provide a liquid propellant system capable of adaptationupon all firearms regardless of type or size. A further object of thisinvention is to provide a gun embodying all the fea tures in combinationdiscussed above. And another object of this invention is to provide aliquid propellant type g'uri capable of being maintained in ready-firecondition for indefinite periods. Other objects will become apparent tothose skilled in the art upon reading the following detailed disclosureand drawings in which:

But heretofore a successful 2,922,341 Patented Jan. 26, 1960 ice Figure1 discloses a schematic drawing of the system of this invention showinga cartridge in position to be fired, with the regenerative injectionmeans ready to be activated.

Figure 2 is a schematic drawing showing the system just after the primerof the projectile has been ignited and the regenerative injection meansbeginning to operate.

Figure 3 is a schematic drawing showing the system as it appears atsubstantially the end of the metering stroke of the regenerativeinjection means.

Figure 4 is a broken perspective view of an embodiment of a projectilefor use in the system disclosed in Figures 1 to 3.

Figure 5 is a partial side view of an embodiment of a gun utilizing thesystem disclosed in Figures 1 to 3 and the projectile disclosed inFigure 4.

Figure 6 is a cross sectional view of the gun shown in Figure 11 is abroken perspective view of the parts shown in Figure 9. p j

The objects of this invention are accomplished, broadly speaking, by agun system using an initiating charge which upon beingignited,preliminarily acts upon a metering piston through the force of its gasesto cause an injection of liquid propellant into the chamber of the gun.This liquid propellant then is ignited and the force of its gases drivesa projectile out the bore of the gun. More particularly speaking, theobjects of this invention are accomplished with the use of a .gun whichat the outset ignites an initiating charge to generate gas, the pressureof which used to start the action of the gun. The force of the gasespreliminarily drives a metering diiferential area piston whichforcesliquid propellant by an aidjustk The liquid propellant is ignited theflame of the burning initiatingcharg'e and, therefore, generatesadditional gas" able piston stroke into the'dry chamber of the gun.

pressure. This gas pressure not only drives a projectile out the bore ofthe gun but also drives the metering piston to the end of its stroke.Hence as the projectile travels down the bore of the 'gun, regenerativeinjection of the propellant occurs thereby enabling a desirablepressuretime relationship of the projectile travel in the gun.

The employment of a dry chamber enables not only simpler seals but alsothe possibility of maintaining the gun in ready-fire position withoutfear of leakage or corrosion of the chamber by the liquid propellant.The desirable advantages of pyrotechnic ignition as well as the use of amonopropellant are other features of this invention.

Referring to Figures 1, 2 and 3 which disclose broadly the gun system ofthis invention, there is shown a bore 1 of a gun. Within the rearsection of the bore is a chamber in which is shown a projectile 3 aboutto be fired. The projectile has a band 4 around its base which covers aprimer shown in more detail in Figure 4. The projectile shown is firedby a firing pin 5, which harnmers against band 4 of projectile 3 tocause ignition F of a percussion sensitive primer, the flash of which ignites an initiating charge within the projectile. It should be notedthat other ignition means such as electrical means, separate initiatingmeans within the gun Itself one end of a metering chamber 7. Within themetering chamber is contained a differential area piston 8, the largerarea 9 of the piston facing the inlet of the gas port 6. The smallerarea 10 of the piston 8 is on the opposite side and contacts liquidpropellant 11 contained within'the metering chamber 7. The smaller areais effected by integrally attaching'a guide rod 12 to the liquidpropellant face 10 of the piston. This guide rod acts to guide theproper movement of the piston. The liquid propellant is passed into themetering chamber through inlet 13 containing check valve 14 which onlypermits flow into the chamber. The liquid propellant adapted to hold aninitiating charge for initially activatcontaining section of themetering chamber communicates with injection port 15. Port 15communicates with the chamber 2 of the bore 1, and contains a checkvalve 16 which again only permits flow into the chamber of the bore. 7 l

The operation of the projectile propelling system shown in Figures 1, 2and 3 begins with the loading of projectile 3 into the chamber 2 of thebore 1 and the filling of the metering chamber 7 with the liquidpropellant 11. The projectile 3 contains a percussion type primer and aninitiating charge. The firing-pin 16 is activated to strike the band 4of the projectile 3' thereby igniting the primer and the initiatingcharge of said projectile. Gases from the burning initiating chargetravel into the chamber 2 and through gas port 6 into cylinder. 7. Inthe cylinder they act upon the metering piston 8 and force the liquidpropellant out through injection port 15 into the heretofore dry chamber2. As the propellant enters into the chamber, it is ignited by the flameand heat of the burning initiating charge of projectile 3. Its ignitioncauses an increase in the gas pressure of the chamber as well as in thegas port 6 and metering chamber 7. This increase in gas pressure exertsa continuous increasing force against the piston 8 thereby metering thepropellant 11 into the chamber 2. Also as the pressure increases andsimultaneously with the propellant injection process, the projectile 3is forced down the bore 1. This illustrates the regenerative injectingaction of the system from an initially dry chamber state.

In Figure 4 there is shown an embodiment of a typical projectile for usein a gun such as seen in Figures 5 to 12 which uses the projectilepropelling system of this invention. The projectile shown is of standarddesign having an ogival nose portion 20 and a cylindrical body portion21. The rear portion of the projectile body has a narrower diameter inorder to accommodate a ring or tubular'band 4 which covers a percussiontype primer 23 contained within a wide but shallow groove 24 encirclingthe periphery of the body portion 21. The band 4 is fastened to theprojectile by crimping itsjend portions 25 and 26 inwardly into obliquechannels 27 and 28 respectively upon the body of the projectile. theprojectile is then crimped inwardly upon the crimped end portion 26 ofthe band 4. Theprojectile has an axial cavity 30 in which is containedin initiating charge 31. Radially extending flash ports 32 communicatethe axial cavity 30 with the primer groove 24. The rear end of thecavity 30*is sealed with rupturable and consumable disc 33. s v

The projectile of Figure 4 is fired byjpercussion of a firing pinagainst band 4. Thisignites the primer 23- and' its flash travels downflash ports 32 and contacts initiating charge 31. After ignition of theinitiating charge by the primer flash disc 33 is ruptured and consumed.The gases from the'burning initiating charge are used to initiallyoperate the propelling system as described above and as will bedescribed more fully below with'reference to a gun employing theprojectile shown.

With modifications the system of this invention could employ other typeshells. jectile disclosed in copending patent application entitledIgnition System,, Serial Number 415,537 filed March 11, 1954, nowabandoned,'could be used if theshellrwere Tab 29 of ing the meteringpiston of this system. If desired, one could use cased ammunition inwhich the case contains the primer and the initiating charge and theprojectile is a standard solid slug of metal. Obviously, there are otheruseful projectiles that would be operative.

Figures 5 through 11 illustrate a particular embodiment of a rifleemploying the projectile propelling system of this invention. Obviously,other rifles employing the system could be formulated.

The rifle shown in these figures has a barrel 40 with an axial rifledbore therein. The rear end of the barrel is threaded into a receiverextension 42 which in turn is threaded into a receiver 43. The receiverextension has a chamber 44 into which a projectile 45, similar to thatshown in Figure 4, may be inserted. Chamber seal 47 of bolt 46 seals therear end of the chamber. The

" chamber seal 47 has seal rings 48. Bolt'46 is capable For example, thecaseless proof reciprocable movement within receiver 43. Bolt op.-erating section 49 of operating rod 50 contains an angular cam slot 51,the surfaces of which act to operate the locking lug 52 of the bolt 46.Rearward movement of the operating rod 50 (see Figures 6 and 9) liftsthe locking lug 52 to unlock the bolt. Complete forward movement swingsthe locking lug 52 down to lock the bolt (see Figures 5 and 11). The rod50 has a finger piece 53 and is spring biased forwardly by an operatingrod spring 54. The spring acts to keep the bolt 46 in battery positionthrough the action of the operating rod 50.

Within a vertically disposed annular cavity 57 in the receiver extension42 is a firing pin 58 spring loaded upward by a firing pin spring 59when the pin is cocked.

The pin is cocked when its cocking shoulder 60 is engaged by the searshoulder 61 of trigger 62. A firing pin cocking cam pin 63 extendshorizontally outward from firing pin 58. It is engaged by an oblique camsurface 64 on the undersurface of the forward section of the operatingrod 50. The firing pin is depressed downward on the rear or cockingstroke of the operating rod. Around the forward surface of the firingpin body is an annular groove 66 which acts as a gasseal. The primerstriking portion 67 of the pin 58 is of small diameter. Resting upon theshoulder between the body and the primer striking portion 67 of thefiring pin 58 is a washer 68 of resilient material such as rubber,neoprene and the like and a metallic washer 69. (See Figure 6.) Theseact as the primary seal against leakage downward from the chamber intothe firing pin cavity.

The trigger 62 is contained within the receiver extension 42 and ispivoted about trigger pin 70. The finger piece 71 of the trigger extendsinto a space enclosed by trigger guard 72. A trigger spring 74 normallyspring biases the trigger in a counter-clockwise fashion about triggerpin 70. A conventional notched cross bar safety 73 can operate upon thetrigger to prevent its movement.

In a forwardly extending horizontal cavity forward of the trigger andfiring pin assemblies is a gas metering and injection system. The systemconsists of the cavity 80 which is the cylinder. Within the 'cavity is apiston 81 having seal rings 82. Extending forwardly from the piston 81is a hollow tubular guide rod 83 having propellant port 84. A needlevalve 86 disposed between guide rod 83 and metering plunger 87 acts as aflame arrestor and closes off the forward end of the hollow opening ofthe guide rod until the needle valve is pushed forward past port 106 andthe needle valve have seal rings 88 and 89 respectively at their frontends to prevent leakage. Seal ring 88 prevents forward leakage of theliquid propellant into the needle valve cavity. Seal ring 89 preventsforward leakage of the propellant gases that may travel down port 106and of liquid propellant into the plunger and plunger spring cavity. Theplunger 87 which bears against the needle valve member is spring biasedrearwardly by a plunger spring 90. The spring and the plungerarenormallyhoused within, a plunger housing- 91 which is threaded intothe receiver extension 42 beneath the barrel 40. The forward end of theplunger housing is plugged by a threaded plunger housing plug 92. Abushing 93 around the neck of plunger 87 acts as a guide upon the strokeof the plunger. Vents 94 and 95 relieve any pressure built up within theplunger houslng.

Cavity 80 within the receiver extension is sealed at its rearwardopening by a threaded plug 100 (see Figures 5 and 12 especially). Theplug has a peripheral groove 101 into which gas port 102 enters. Theport directs propellant gases from the chamber 44 into groove 101. Afterentering into groove 101, the gases are directed against metering piston81 by plug gas port 103. In order to increase the effectiveness of thegases in moving the piston 81 forward, a pocket 104 may be cupped intothe head of the piston. Plug 105 seals the hole that was required to bemade for drilling gas port 102.

Needle valve 86 acts as a fia-me arrestor preventing flame that maytravel down port 106 from contacting the propellant charge in thecompression chamber 80. Propellant port 106 leads from the needle valvecavity into valve assembly 107 (see Figures 8 and 11 especially). Whenthe needle valve is pushed forward past the opening of the port, theliquid propellant flows upward into the port 106 and into the valveassembly. The valve assembly has a threaded tubular member 108. Thetubular member has an annular shoulder 109 within its axially locatedcavity 110 which acts as a stop against ball 111. Ball 111 is detachablysecured to a plunger 112 which is spring biased outwardly from theshoulder 109 of the annular cavity by valve spring 113. This springbiasing outwardly seats ball 111 upon the axial opening of the shoulder109. Plug 114 is threaded into tubular member 108. A peripheral groove115 around the tubular member 108 with radial ports 116 lead thepropellant into the interior of the tubular member. Injection port 117extends from the ball portion cavity of the tubular member 108 to thechamber 44 of the gun. A seal 118 prevents leakage around the threads.

The metering piston 81 is loaded with liquid propellant through aninjection port 125. This port is within a threaded nipple 126. Apropellant supply conduit 127 connects the tank 124 with the port 125.At the inner end of the nipple is a counterbored cavity 129 in which iscontained a check valve 130 biased by spring 131. Ports 132 and 133 leadinto the volume enclosed by the needle valve 86 and metering cavity 80.An air bleed valve 134 vents the volume of the propellant supply conduit127 and part of the volume of the injection port 125 on the outer sideof the check valve 130.

Within the receiver 43 and to the rear of the metering assembly in thereceiver extension 42 is a magazine 120 in which caseless projectiles 45are stored until use. A magazine spring 121 and a magazine follower 122force the projectiles 121 upwardly in dispensing fashion to the bolt 46.The magazine is held in place by a magazine catch 119.

Within gun stock 123 is contained a tank 124 for storage of liquidpropellant (see Figure 9). The propellant within the tank is transferredto the metering assembly of the gun by pressure induced within the tankthrough operation of a hand operated pressure pump 135. This pressureforces the liquid propellant out through supply conduit 127, into theinjection port 125 of the gun and then into the propellant chamber 85 ofthe metering cavity 80.

To operate the gun of Figures 5 to 12, tank 124 within gun stock 123 isfirst loaded with liquid propellant. A magazine 120 containing caselessprojectiles 118 of the design shown in Figure 4 is inserted into themagazine opening with the receiver 43. Magazine catch 119 holds themagazine in place. Trigger safety is placed in an on position. Theliquid propellant in tank 124 is next pumped into metering cavity 80 byhand operation of pressure pump 135. The pump builds up pressure withinthe tank forcing the propellant out through supply conduit 127 throughthe injection port 125 and into metering cavity shown in Figure 5. Thepressure in the tank may be built up to the point that hand pumping willonly be required after a series of rounds have been fired-the number ofthe series depending upon the pres sure. Use of the reciprocatingactions of the bolt could also be used to maintain the pressure betweenthe injection port 125 and cavity 80, the propellant flows through checkvalve 130 (see Figure 8) through ports 132 and 133 (see Figure 8) andinto the compression chamber of the metering assembly by feed port 78.Feed port 78 leads directly from ports 132 and 133 into the compres sionchamber. The propellant supply conduit is bled free of air when firstfiring by air bleed valve 134. Next operating rod 50 is pulledrearwardly. This movement cocks the firing pin 58 by action of camsurface 64 of the rod acting against cocking cam pin 63 to depress thefiring pin against spring 59. The sear shoulder 61 of the trigger 62engages the cocking shoulder 60 of the firing pin when the pin issufficiently depressed downwardly. Movement of the operating rod alsocauses unlocking of the bolt 46 by swinging locking lug 52 upwardlythrough action of angular cam slot 51 of the rod 50, and rearwardmovement of the bolt. Upon release of the rod 50, operating rod spring54 causes forward movement ofvthe rod and bolt. A caseless projectile isswept off the top of the stock of caseless projectiles of the magazine,and into the chamber 44 of the receiver extension 42. The bolt is lockedat the completion of the reload stroke by action of cam slot 51 uponlocking lug 52.

The gun is fired by placing the safety 73 in an oif" position andpulling the finger piece 71 of the trigger 62 rearwardly. This causesthe sear shoulder 61 of the trigger to release the cocking shoulder 60of the firing pin. The pin is driven by force of firing pin spring 59into the band of projectile 45. The percussion type primer 23 under theband 22 is thereby ignited (see Figure 4). The flash from the ignitedprimer 23 travels through flash holes 32 and onto the initiating charge31. The initiating charge becomes ignited and in burning generates gaspressure which travels through gas port 102, groove 101 of plug 100,plug gas port 103 and into pocket 104 of the metering piston 81. Themetering piston is driven forwardly by these gases against the force ofthe plunger spring 90. As this occurs, liquid propellant contained inpropellant chamber is driven out of said chamber through port 84,through the cavity of guide rod 83, and into the volume rearward of theneedle valve 86. When the needle valve 86 is driven forwardly past port106, the propellant is driven upwardly through propellant port 106,through the valve assembly 107 and then into the chamber 44 of the gun.In the valve assembly 107, the propellant flows around tubular member108, in groove 115, then into radical ports 116, around plunger 112,against ball 111 and through injection port 117. After entering into thechamber, the propellant burns generating additional gas pressure whichis used to continue the injection system just described and to drive theprojectile 45 out the bore 41 of the gun. This continuous injection ofthe propellant as it burns and as the projectile travels is known asregenerative injection. It should be noted that the chamber 44 wasinitially in a dry state until the burning initiating charge 31 causedinjection of propellant into said chamber. By adjustment of the force ofspring through plug 92, the metering rate can be controlled for optimumenergy usage of the propellant. In use, monopropellants are operablebecause burning is already present in the chamber when said propellantis used.

Obviously, the projectile propelling system is useful for all caliberweapons. Other designs for the gun and the projectile including themanner of ignition, type of projectile employed, the valve arrangementof the metering '7 system, the liquid propellantstorage system,adaptation to automatic operation and other features not recited arepossible and can be made without departing from-the spirit and scope'ofthe-invention as set forth in theappended claims; I

The invention having thus been described what is desired to be securedby Letters Patent is as follows:

l. A liquid propellant gun comprising a receiver, a receiver extensionfixed to said receiver and containing a chamber, ignition means, aliquid propellant metering assembly, a barrel fixed to the receiverextension, a reciprocating bolt operable to seal one end of the chamber,a projectile operable to seal the opposite end of the chamber and aliquid propellant supply, said metering assembly including a meteringcylinder and a metering piston, one face of the piston cooperating withthe cylinder to define a metering-cavity, the opposite face of thepiston cooperating with the cylinder to define a pressure pocket,conduit means connectingthe metering 'cavity with the chamber andconnecting the chamber with the pressure pocket, a one-way valvedisposed in the metering cavity conduit means effective to permit fluidflow in circulatory fashion from the metering cavity to the chamber andthence to the pressure pocket Whenever the piston is moved in adirection which tends to pressure fluid within the metering cavity. I IQ 2. A liquid propellant gun comprising a receiver, a receiver extensionfixed to receiver, a projectile and a liquid propellant supply, a barrelfixed to the receiver'extension,

a bore extending through the barrel and the receiver extension, a boltcavity formed in the receiver and intersecting the bore, a reciprocatingbolt disposed within the bolt cavity and operable'flto seal one end ofthe bore, said projectile being effectivto seal the opposite end of thebore, said receiver extension containing an ignition means and a liquidpropellant metering assembly, said assembly comprising a meteringcylinder, a differential area piston disposed in the cylinder andcarrying a tubular guide rod, a conduit leading from the bore to oneside of the piston, a second conduit leading from the opposite side ofthe piston through said guide rod to the bore and means for introducingpropellant to the opposite side of the piston, said second conduitcontaining'a flow control means.

3. A liquid propellant gun as defined in claim 2 wherein the flowcontrol means comprises an adjustable needle valve.

References Cited in the file of this patent 'UNITED STATES PATENTS1,291,674 Brannon Jan. 14, 1919 2,088,503 Broussard July 27, 19372,129,875 Rost Sept. 13, 1938 2,307,369 Ferrel Jan. 5, 1943 2,408,252DeGanahl Sept. 24, 1946 2,574,147 Hobbs Nov. 6, 1951 2,683,963 ChandlerJuly 20, 1954 FOREIGN PATENTS 560,813 Great Britain Apr. 21, 1944631,498 Great Britain Nov. 3, 1949 1,003,687 France Nov. 21, 1951

